Quest for processing in P5000

[Mary Tang]

Hi all --

I would suggest that this is OK to process in p5000etch ChB because Pt 
is not exposed to plasma and Pt is considered a "semiclean B" material 
if it were deposited in a MOS-compatible backend system.   If this was 
deposited in innotec or metalica,  it is technically "contaminated."  
However, contamination of the etch chamber via sputtering under these 
conditions is not very likely.  That said, contamination of the PRS1000 
bath when cleaning the resist in wbmetal could present risk 
contamination, so I'd suggest for this case, that cleans be manually 
done at wbgeneral (after matrix ashing.)

Any comments or concerns about this approach?

Mary


On 8/4/2011 7:37 PM, Lele Wang wrote:
> Dear Committee,
> I sent this email earlier but without reply. I tried other tools but it did not work so I am stuck on this step for 1 month.
>
> My wafer is in the contaminated group with Pt metal lines on top. I need to do a directional oxide etch at the bottom of the trench in P5000 and the wafer will be well protected by 1.6um photoresist on top. The opening area is a 30um deep, 5um wide silicon trench having thermal oxide on sidewall and bottom, which is clean. The bottom oxide to be etched is 800nm. Is that ok to etch this in p5000? Please reply ASAP. Thanks a lot.
>
>
>
> Best,
> Lele Wang
> Department of Electrical Engineering